Fast, easy evaluation of capacitive

sensors

Key features

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` 8-channel`capacitive`sensor`PCF8885

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` 2-channel`capacitive`sensor`PCA8886

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` LCD/LED`driver`PCF8536

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` Cortex-M0`LPC1111`with`8`KB`flash`memory

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` Standalone`operation

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` Powered`via`two`AA`batteries`or`USB

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` Software`modifications`via`LPC-Link

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` Sounder`for`audible`feedback

Applications

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` Hermetically`sealed`keyboards

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` Proximity`detection

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` Switches`in`medical`and`explosive`environments

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` Vandal-proof`switches

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` Gaming`devices

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` Portable`communications

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` Fixed`and`mobile`entertainment`systems

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` White`goods

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` Automotive`(e.g.`passive`keyless`entry)

This`board,`equipped`with`an`LCD`driver`and`controlled`by`a`Cortex-M0™`MCU,`demonstrates`the`

features`of`two`capacitive`sensor`devices.

The`NXP`OM11057`demonstrates`the`features`of`the`PCF8885,`

an`8-channel`capacitive`sensor,`the`PCF8886,`a`2-channel`

capacitive`proximity`sensor`and`the`PCF8536,`an`LCD/LED`

controller`which`can`be`used`to`drive`an`LCD`and`the`

accompanying`backlight.`The`board`is`controlled`by`a`

low-cost,`32-bit`Cortex-M0`microcontroller`LPC1111.``

An`LPC-Link`debug`probe`is`also`included`with`the`board,`

so`designers`can`easily`modify`the`firmware`or`reprogram`

the`LPC1111`using`NXP’s`low-cost`LPCXpresso`development`

platform.

The`sensor`PCF8885`is`configured`to`control`a`total`of``

20`sensors:`the`slider`(eight`channels),`the`wheel`(eight`

channels),`and`four`buttons.`The`device’s`very`high`sensitivity`

delivers`reliable`operation,`even`though`it’s`covered`by`

plexiglass`(acrylic`glass).`The`proximity`sensor`PCA8886`

uses`one`of`its`two`channels`to`detect`whether`a`hand`is`

approaching`the`controls.`The`other`channel`can`be`connected`

to`an`external`sensor.`The`LCD/LED`driver`PCF8536`controls`

both`of`the`board’s`LCDs`using`a`multiplex`rate`of`eight.`

NXP capacitive sensor

demo board OM11057